Effect of dietary n 3 series fatty acids on sperm production in the freshwater crayfish Astacus leptodactylus Eschscholtz Astacidae

The objective of the present work was to evaluate the effects of three different rates of long chain n-3 polyunsaturated fatty acid (LC n-3 PUFA) on the sperm number of Astacus leptodactylus. The experiment was carried out with the four following treatments: control group (not supplemented LC n-3 PUFA), D1 (1 %), D2 (2 %) and D3 (3 %). The sperm number of A. leptodactylus was counted; the reproductive system was weighted; and the macroscopical analysis of the testes and vasa deferentia (DVD) were conducted. In addition, gonado-somatic index (GI) and testes index (TI) were also calculated. The results showed that there was a significant difference between the crayfish fed LC n-3 PUFA supplemented diets (D1, D2, D3) and control in mean sperm number (P 0.05), but there was not a significant difference in the TI of the crayfish fed control, D1, D2 and D3 (P > 0.05). In conclusion, diets containing different levels of LC n-3 PUFA significantly increase the sperm number of A. leptodactylus, and they are crucial for the production of higher number of sperm in this species